U.S. patent application number 12/039116 was filed with the patent office on 2008-07-03 for management method and an apparatus for reverse link in a multicarrier wireless communication system.
This patent application is currently assigned to Huawei Technologies Co., Ltd.. Invention is credited to Peng Li.
Application Number | 20080159248 12/039116 |
Document ID | / |
Family ID | 36867345 |
Filed Date | 2008-07-03 |
United States Patent
Application |
20080159248 |
Kind Code |
A1 |
Li; Peng |
July 3, 2008 |
MANAGEMENT METHOD AND AN APPARATUS FOR REVERSE LINK IN A
MULTICARRIER WIRELESS COMMUNICATION SYSTEM
Abstract
In a reverse link management method in a multicarrier wireless
communication system, an access terminal AT sends a Reverse Link
Management Message to an access network AN. The Reverse Link
Management Message carries information of the reverse link that the
AT dropped. The AN sends the Traffic Channel Assignment Message to
AT, and assigns a new reverse carrier link according to the
received the Reverse Link Management Message. The AT establishes a
reverse carrier link (reverse link) based on said Traffic Channel
Assignment Message and transmits data on the new reverse carrier
link. According to this method, the AT can actively report the
number of its containing reverse links to AN and inform the AN of
the reverse links it has dropped, without further modifying other
messages and steps in terminal connection process.
Inventors: |
Li; Peng; (Shenzhen,
CN) |
Correspondence
Address: |
DARBY & DARBY P.C.
P.O. BOX 770, Church Street Station
New York
NY
10008-0770
US
|
Assignee: |
Huawei Technologies Co.,
Ltd.
Shenzhen
CN
|
Family ID: |
36867345 |
Appl. No.: |
12/039116 |
Filed: |
February 28, 2008 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
PCT/CN2006/002121 |
Aug 21, 2006 |
|
|
|
12039116 |
|
|
|
|
Current U.S.
Class: |
370/342 |
Current CPC
Class: |
H04L 5/0091 20130101;
H04W 76/15 20180201; H04L 1/1607 20130101; H04L 27/2601 20130101;
H04L 1/0025 20130101 |
Class at
Publication: |
370/342 |
International
Class: |
H04B 7/216 20060101
H04B007/216 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 28, 2005 |
CN |
200510036885.1 |
Claims
1. A reverse link management method used in a multicarrier wireless
communication system, comprising the steps of: sending, by an
Access Terminal, a Reverse Link Management message to an Access
Network, the Reverse Link Management message carrying information
of one or more reverse carrier links that the Access Terminal has
dropped.
2. The method according to claim 1, further comprising: assigning,
by the Access Network, one or more reverse carrier links according
to the received Reverse Link Management message and sending a
Traffic Channel Assignment message to the Access Terminal;
establishing, by the Access Terminal, the one or more reverse
carrier links according to the Traffic Channel Assignment
message.
3. The method according to claim 1, wherein the Reverse Link
Management message is transmitted on a reverse access channel or a
reverse traffic channel.
4. The method according to claim 1, wherein the Reverse Link
Management message carries information of the number of reverse
carrier links that the Access Terminal currently can support.
5. The method according to claim 1, wherein the Reverse Link
Management message contains a message sequence number, a link
dropped indication and reverse link index information
6. The method according to claim 5, wherein reverse link index
information of the Reverse Link Management message corresponds with
the one or more reverse carrier links assigned according to the
Traffic Channel Assignment message.
7. A reverse link management method used in a multicarrier wireless
communication system, comprising the steps of: sending, by an
Access Terminal, a first Reverse Link Management message or a
second Reverse Link Management message to an Access Network, the
first Reverse Link Management message carrying information of one
or more reverse carrier links that the Access Terminal has dropped
and the second Reverse Link Management message carrying information
of the number of reverse carrier links that the Access Terminal
currently can support.
8. The method according to claim 7, further comprising the steps
of: sending, by the Access Network, a Traffic Channel Assignment
message to the Access Terminal so as to assign one or more new
reverse carrier links according to the received first Reverse Link
Management message or the received second Reverse Link Management
message; and establishing, by the Access Terminal, the one or more
new reverse carrier links according to the Traffic Channel
Assignment Message.
9. The method according to claim 7, wherein the first Reverse Link
Management message or the second Reverse Link Management message is
transmitted on a reverse access channel or an existing reverse
traffic channel.
10. The method according to claim 7, wherein the first Reverse Link
Management message contains a message sequence number, a link
dropped indication and reverse link index information.
11. The method according to claim 10, wherein reverse link index
information of the first Reverse Link Management message
corresponds with the one or more new reverse carrier links assigned
according to the Traffic Channel Assignment message.
12. A reverse link management apparatus used in a multicarrier
wireless communication system, comprising: an Access Terminal
adapted to send a Reverse Link Management message to an Access
Network, the Reverse Link Management message adapted to carry
information of one or more reverse carrier links that the Access
Terminal has dropped.
13. The reverse link management apparatus according to claim 12,
wherein the Reverse Link Management message is adapted to carry
information of the number of reverse carrier links that the Access
Terminal currently can support.
14. The reverse link management apparatus according to claim 12,
wherein the Access Terminal further comprises: a link control unit;
and a message transmission unit adapted to send the Reverse Link
Management message to the Access Network according to a control
signal sent by the link control unit, wherein the link control unit
is adapted to receive a Traffic Channel Assignment message sent by
the Access Network and to control the Access Terminal to establish
one or more reverse carrier links according to the Traffic Channel
Assignment message.
15. The method according to claim 2, wherein the Reverse Link
Management message is transmitted on a reverse access channel or a
reverse traffic channel.
16. The method according to claim 2, wherein the Reverse Link
Management message carries information of the number of reverse
carrier links that the Access Terminal currently can support.
17. The method according to claim 2, wherein the Reverse Link
Management message contains a message sequence number, a link
dropped indication and reverse link index information
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a Continuation of PCT/CN2006/002121
filed Aug. 21, 2006, and claims the benefit of Chinese Patent
Application No. 200510036885.1 filed on Aug. 28, 2005, both of
which are incorporated by reference herein. The PCT application
published in Chinese as WO2007/025460 A1.
FIELD OF THE INVENTION
[0002] The present invention relates to the field of wireless
communication technology, and in particular to a management method
and an apparatus for reverse link in a multicarrier wireless
communication system.
BACKGROUND OF THE INVENTION
[0003] Single-carrier transmission is adopted in the existing
CDMA2000 1xEvolution-Data Optimized (1xEV-DO) technology. In a
1xEV-DO system, an Access Terminal (AT) only uses one reverse
carrier link to transmit information.
[0004] A higher data transmission rate is required for the
development of data services. The Third Generation Partnership
Project 2 (3GPP2) has proposed a new air interface evolution plan.
In the first phase of the plan, a great increase in air interface
data rate is enabled through Multiple Carrier EV-DO (NxEV-DO). It
is required that the forward data rate is no lower than N.times.3.1
Mbps and the reverse data rate is no lower than N.times.1.8 Mbps,
in which N is the number of carriers used by an Access Network (AN)
or the AT. Further, it is required that the forward and reverse
carriers be assigned dynamically and independently through the
cooperation of the AN and the AT. The number of forward carriers
and the number of reverse carriers are not required to be
symmetric.
[0005] In an NxEV-DO system, an AT should be able to request an AN
for the number of reverse carrier links the AT can support
according to the AT's current power amplification state or other
factors, and also be able to drop one or more reverse carrier links
according to its power amplification state or other factors and
report this to the AN.
[0006] FIG. 1 is a diagram illustrating the structure of a 1xEV-DO
system, where the direction of a forward carrier link is defined
from the AN to the AT and the direction of a reverse carrier link
is defined from the AT to the AN. The components of the 1xEV-DO
system are respectively described as follows:
[0007] Access Network (AN) is a network equipment configured to
provide data connectivity between a packet switched data network
(typically the Internet) and the ATs, and the AN is equivalent to a
base station in a CDMA2000 system.
[0008] A packet Control Function unit (PCF unit) mainly provides
between a wireless link and a wire link functions such as mapping,
call control, mobility management, session management, data
buffering and forwarding, and accounting information
collection.
[0009] A packet Data Serving Node (PDSN) mainly provides functions
such as link management, mobility management, address distribution,
accounting information collection, data routing and tunnel
encapsulation, and also supports the function of foreign agency for
Mobile IP.
[0010] An accounting, Authentication, Authorization server (AAA
server) mainly provides functions such as identity authentication
and address distribution.
[0011] A mobile Switching Center (MSC) is a circuit domain voice
switching center through which the circuit domain voice service is
introduced.
[0012] In the existing 1xEV-DO system, when performing a
configuration negotiation or establishing a traffic channel, the AT
needs to establish a connection. There are mainly the following
situations:
[0013] The AT initiates a connection request on its own
initiative;
[0014] The AN sends a paging message, and the AT initiates a
connection request when receiving the paging message;
[0015] The AT initiates a connection request when an initial
establishment of a session or a configuration negotiation is
required.
[0016] As shown in FIG. 2, the message flow in the case that the AT
initiates a connection request on its own initiative includes the
following processes.
[0017] S01: The AT sends a Connection Request.
[0018] S02: The AT sends a Route Update message to indicate the
wireless circumstance.
[0019] S03: The AN sends a Media Access Control (MAC) layer
Acknowledgement message to confirm that the Route Update message is
received.
[0020] S04: The AN sends a Traffic Channel Assignment message.
[0021] S05: The AT establishes a Reverse Traffic Channel (RTC) and
sends a pilot signal and a Data Rate Control (DRC) signal.
[0022] S06: The AN sends an RTC ACK message to confirm that the RTC
is received.
[0023] S07: The AT sends a Traffic Channel Complete message on the
reverse traffic channel.
[0024] S08: The AT starts to exchange data with the AN.
[0025] It can be seen from the prior art:
[0026] The AT is unable to request the AN for a reverse carrier
link;
[0027] The AN does not know the number of reverse carrier links
desired by the AT;
[0028] Only one reverse carrier link can be assigned to the AT, and
the peak rate of the reverse carrier link is just 1.8 Mbps;
[0029] The forward and reverse data rates can not meet the
requirement of the future service.
SUMMARY OF THE INVENTION
[0030] An embodiment of the invention provides a reverse link
management method in a multicarrier wireless communication system,
so that the AT can flexibly adjust the reverse carrier links
according to its capability of supporting the reverse carrier
links.
[0031] A reverse link management method used in a multicarrier
wireless communication system according to an embodiment of the
invention includes:
sending, by an Access Terminal, a Reverse Link Management message
to an Access Network (AN), the Reverse Link Management message
carrying information of one or more reverse carrier links that the
Access Terminal has dropped.
[0032] Preferably, the Access Network assigns one or more reverse
carrier links according to the received Reverse Link Management
message and sends a Traffic Channel Assignment message to the
Access Terminal;
the Access Terminal establishes the one or more reverse carrier
links according to the Traffic Channel Assignment message.
[0033] Preferably, the Reverse Link Management message is
transmitted on a reverse access channel or a reverse traffic
channel.
[0034] Preferably, the Reverse Link Management message carries
information of the number of reverse carrier links that the Access
Terminal currently can support.
[0035] Preferably, the Reverse Link Management message contains a
message sequence number, a link dropped indication and reverse link
index information.
[0036] Preferably, a correspondence relationship exists between the
reverse link index information of the Reverse Link Management
message and the one or more reverse carrier links assigned
according to the Traffic Channel Assignment message.
[0037] Another reverse link management method according to an
embodiment of the invention includes the following processes:
sending, by an Access Terminal, a first Reverse Link Management
message or a second Reverse Link Management message to an Access
Network (AN), the first Reverse Link Management message carrying
information of one or more reverse carrier links that the Access
Terminal has dropped and the second Reverse Link Management message
carrying information of the number of reverse carrier links that
the Access Terminal currently can support.
[0038] Preferably, the reverse link management is further
implemented through the following processes:
the Access Network sends a Traffic Channel Assignment message to
the Access Terminal so as to assign one or more new reverse carrier
links according to the received first Reverse Link Management
message or the received second Reverse Link Management message; the
Access Terminal establishes the one or more reverse carrier links
according to the Traffic Channel Assignment message.
[0039] Preferably, the first Reverse Link Management message or the
second Reverse Link Management message is transmitted on a reverse
access channel or in an existing reverse traffic channel.
[0040] Preferably, the first Reverse Link Management message
contains a message sequence number, a link dropped indication and
reverse link index information.
[0041] Preferably, a correspondence relationship exists between the
reverse link index information of the first Reverse Link Management
message and the one or more new reverse carrier links assigned
according to the Traffic Channel Assignment message.
[0042] An Access Terminal is further provided according to an
embodiment of the invention, which includes a terminal entity, a
link control unit and a message transmission unit, wherein
the message transmission unit sends a Reverse Link Management
message to an Access Network (AN), according to a control signal
sent by the link control unit; the link control unit receives a
Traffic Channel Assignment message sent by the Access Network, and
controls the Access Terminal to establish one or more reverse
carrier links according to the Traffic Channel Assignment
message.
[0043] To sum up, in the technique solution of an embodiment of the
invention, the Access Terminal can request the Access Network for
the desired number of reverse carrier links and also can report to
the Access Network the information of one or more reverse carrier
links the Access Terminal has dropped.
[0044] The Reverse Link Management message does not make any
modification to the existing messages. Therefore, the backward
compatibility can be kept.
[0045] The Reverse Link Management message has a short length and
occupies less air interface wireless resource.
[0046] The Access Terminal may request or drop one or more reverse
carrier links dynamically and flexibly according to need.
[0047] The Access Terminal sends a Reverse Link Management message
to the Access Network on an access channel to request the number of
reverse carrier links supported by the Access Terminal according to
its current situation (such as the power amplification state and
the data quantity in a buffer). Therefore, the Access Terminal can
make fully use of the power amplification resource and increase the
utilization rate of the air interface wireless resource.
BRIEF DESCRIPTION OF THE DRAWINGS
[0048] The invention will become more readily apparent from the
Detailed Description of the Invention, in which:
[0049] FIG. 1 is a diagram illustrating the structure of a 1xEV-DO
system in the prior art;
[0050] FIG. 2 is a flowchart illustrating an AT initiating a
connection request on its own initiative in the prior art;
[0051] FIG. 3 is a block diagram illustrating the structure of an
exemplified access terminal according to an embodiment of the
invention;
[0052] FIG. 4 is a flowchart illustrating a method according to an
embodiment of the invention; and
[0053] FIG. 5 is a flowchart illustrating a method according to
another embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0054] In order to make the principle, characteristic and advantage
of the invention clearer, the specific embodiments of the invention
will be described by taking an NxEV-DO system as an example with
reference to the attached drawings.
[0055] The embodiments of the present invention can be applied to
the NxEV-DO system and also are compatible with the 1xEV-DO system.
The improvement is made on the C.S0024-A-V1.0 protocol.
[0056] FIG. 3 is a schematic diagram illustrating the structure of
an AT 10 of an embodiment of the invention. It can be seen from
FIG. 3, two functional units are added to the existing terminal: a
reverse carrier link control unit 2 and a message transmission unit
1.
[0057] By using the two functional units, the AT 10 may exchange
reverse carrier link messages with the AN 20 and control to
establish one or more reverse carrier links.
[0058] Specifically, the message transmission unit 1 sends a
Reverse Link Management message to the AN 20 according to a control
signal sent by the reverse carrier link control unit 2.
[0059] The reverse carrier link control unit 2 receives a Traffic
Channel Assignment message sent by the AN 20, and establishes one
or more reverse carrier links of the AT 10 according to the Traffic
Channel Assignment message.
[0060] A Reverse Link Management message is set in an embodiment of
the invention. The message can indicate the number of reverse
carrier links the AT can support currently and also can indicate
the information of one or more reverse carrier links the AT has
dropped. The Reverse Link Management message is sent by the AT to
the AN.
TABLE-US-00001 TABLE 1 Field Information of the Reverse Link
Management message Field Length (bits) MessageID 8 MessageSequence
8 LinkDroppedIndication 1 Num of Reverse Links 4
[0061] The following fields appear multiple times according to the
value of the field Num of Reverse Links:
##STR00001##
[0062] Firstly, the above fields are respectively explained as
follows:
[0063] Message ID refers to a message identification. Message IDs
are used to distinguish different messages so that each message
corresponds to a unique Message ID.
[0064] MessageSequence refers to a message sequence number. The AT
sets this field to take the MessageSequence value of the latest
Traffic Channel Assignment message it received.
[0065] LinkDroppedIndication refers to a link dropped indication.
If this field is set to `1`, the message indicates that the AT 10
reports information of one or more reverse carrier links the AT 10
has dropped to the AN 20. If this field is set to `0`, the message
indicates that the AT 10 reports the number of reverse carrier
links the AT 10 can support currently to the AN 20.
[0066] Num of Reverse Links refers to the number of reverse
links.
[0067] If the LinkDroppedIndication is "0", the field Num of
Reverse Links indicates the number obtained by subtracting 1 from
the number of reverse carrier links which the AT 10 reports to the
AN 20 it can support. If the LinkDroppedIndication is "1", the
field Num of Reverse Links indicates the number obtained by
subtracting 1 from the number of reverse carrier links the AT 10
has dropped.
[0068] ReverseLinkIndex refers to a reverse link index. The field
ReverseLinkIndex is included in the message only when the
LinkDroppedIndication field is "1". Otherwise, the field
ReverseLinkIndex is not included in the message. The field
ReverseLinkIndex is consistent with the sequence of the reverse
carrier frequency points indicated by the Traffic Channel
Assignment (TCA) message in step S12 of FIG. 4 which has the same
MessageSequence field as that of the message including the field
ReverseLinkIndex. For example, if the field ReverseLinkIndex is
`0000`, it indicates a reverse carrier link with the lowest
frequency point in the corresponding TCA message. If the field
ReverseLinkIndex is `0001`, it indicates a reverse carrier link
with the frequency point immediately next to the lowest frequency
point in the TCA message. The rest cases may be deduced by
analogy.
[0069] Reserved refers to this field is reserved. The field
Reserved is set to be all `0` by the AT 10, and the number of `0`
makes the length of the message be integral times of 8 bits.
TABLE-US-00002 TABLE 2 information fields of the message
##STR00002## ##STR00003## ##STR00004## ##STR00005##
[0070] Information fields in table 2 need to be included in each of
the messages, in which:
[0071] Channel: This field indicates which channel can be used to
transmit this message and the channel may be for example an AC or a
RTC.
[0072] Addressing: This field indicates that this message is
transmitted in a unicast mode rather than in a broadcast mode or in
a multicast mode.
[0073] SLP: This field indicates that this message is transmitted
in a best effort mode. In the best effort mode, the message is sent
only once and the message may be erased in the transmission.
[0074] Priority: This field indicates the priority of sending this
message where the smaller the number is, the higher the priority
is.
[0075] FIG. 4 is a flowchart illustrating a method of initiating a
Reverse Link Management message by an idle AT 10 on its own
initiative according to an embodiment of the invention. As shown,
the method includes the following processes:
[0076] S11: The AT 10 sends a Reverse Link Management message on an
access channel to the AN 20, by means of which the AT 10 requests
the number of reverse carrier links the AT 10 can support according
to the AT's current condition (e.g., power amplification state,
data quantity in the buffer).
[0077] S12: The AN 20 sends a Traffic Channel Assignment message
according to the received Reverse Link Management message and the
Traffic Channel Assignment message includes specific information of
the forward and reverse channels.
[0078] In the NxEV-DO system, the Traffic Channel Assignment
message sent by the AN 20 needs to be expanded on the basis of
C.S0024-A-V1.0. The Traffic Channel Assignment message includes
information of relevant channels.
[0079] The forward channel information includes carrier frequencies
of one or more forward carrier links, sector information for
transmission of the forward channel, MAC index information assigned
to the AT 10 for identifying data packets transmitted to the AT 10
and so on.
[0080] The reverse channel information includes carrier frequencies
of one or more reverse carrier links, MAC index information of a
power control channel (a forward channel used for controlling the
transmission power of the reverse channel), forward channel index
information for transmitting the power control channel and so
on.
[0081] S13: The AT 10 establishes one or more newly assigned
reverse carrier links according to the contents contained in the
Traffic Channel Assignment message and sends a pilot signal and a
DRC signal to the AN 20.
[0082] The reverse pilot channel is mainly provided to help the AN
20 to hunt a reverse channel and to implement coherent
demodulation.
[0083] The DRC channel is a data rate control channel transmitted
by the AT 10 for notifying the AN 20 of the forward traffic channel
rate requested by the AT 10 and the service sector selected by the
AT 10.
[0084] S14: The AN 20 sends an RTC ACK message to acknowledge
receipt of the reverse traffic channel.
[0085] S15: The AT 10 sends a Traffic Channel Complete message on
the reverse traffic channel and shuts down the timer.
[0086] The AT 10 starts the timer when sending the connection
request. If the connection can be established within the time
period determined by the timer, the timer is shut down. Otherwise,
the time period determined by the timer expires and the AT 10 is
changed to another state.
[0087] S16: The AT 10 and the AN 20 start to exchange data on both
the prior and newly assigned traffic channels.
[0088] FIG. 5 is a specific flowchart illustrating a method of
initiating a Reverse Link Management message by an AT 10 in the
service state according to another embodiment of the invention. As
shown, the method includes the following processes:
[0089] S21: A traffic channel is established. The process for
establishing the traffic channel is the same as the information
exchange process used by the AT 10 to initiate a connection request
as illustrated in FIG. 2 and therefore the description is omitted
here.
[0090] S22: After the traffic channel is established, the AT 10
determines whether the reverse carrier links it can support have
changed or whether it has dropped one or more reverse carrier
links.
[0091] S23: The AT 10 sends a Reverse Link Management message to
the AN 20 to request the number of reverse carrier links the AT 10
can support currently or to report information of the one or more
reverse carrier links the AT 10 has dropped.
[0092] S24: The AN 20 sends a Traffic Channel Assignment message to
assign the forward and reverse carrier links. When sending the
Traffic Channel Assignment message, the AN 20 assigns with its best
effort the number of reverse carrier links which can meet the
number requested by the AT 10 according to the received Reverse
Link Management message.
[0093] S25: The AT 10 establishes one or more reverse carrier links
and sends a pilot signal and a DRC signal to the AN 20.
[0094] S26: The AN 20 sends an RTC Ack message to acknowledge
receipt of the reverse traffic channel.
[0095] S27: The AT 10 sends a Traffic Channel Complete message on
the reverse traffic channel.
[0096] In embodiments of the present invention, the AT 10 can send
a Reverse Link Management message to the AN 20 on its own
initiative to request the number of reverse carrier links the AT 10
can support or to report information of one or more reverse carrier
links the AT 10 has dropped. The Reverse Link Management message
does not make any modification to the existing messages. Therefore,
the backward compatibility can be kept. The embodiments of the
invention enable the AT 10 to request or drop one or more reverse
carrier links dynamically and flexibly according to need, and the
AT 10 can make fully use of the power amplification resource and
increase the utilization rate of the air interface wireless
resource.
[0097] In one embodiment of the invention, the function described
above can also be achieved by using two separate messages. One
message is used by the AT 10 to inform the AN 20 of the number of
reverse carrier links the AT 10 can support currently. The other
message is used by the AT 10 to report the information of one or
more reverse carrier links the AT 10 has dropped to the AN 20. The
message exchange flow is in conformity with that shown in FIG. 4 or
FIG. 5.
[0098] While the principle of the present invention has been
illustrated and described with reference to the above embodiments,
the present invention is not limited to this. It is evident that
those skilled in the art may make various changes and modifications
to the present invention without departing from the spirit and
scope thereof. Therefore, the present invention is intended to
include these changes and modifications provided that they fall
within the scope of the appended claims and all forseeable
equivalents thereof.
* * * * *